1. Field of the Invention
The present invention relates, in general, to a boiler for hot water heating mats and, more particularly, to a boiler for hot water heating mats, in which an electric heater is installed horizontally or inclinedly in a hot water heating tank, with a hot water discharging port of the hot water heating tank formed at a height higher than the height of a lower surface of the electric heater or with a retaining wall installed on the inner surface of the bottom of the hot water heating tank so that, even when hot water heated by the electric heater is discharged from the hot water heating tank to a hot water storage tank due to steam pressure formed in the hot water heating tank, a desired amount of hot water remains on the bottom of the hot water heating tank without being discharged to ensure that the electric heater remains partially submerged, and accordingly, the boiler can automatically exhaust air along with expanded steam from the hot water heating tank only by a heating operation of the electric heater without using a conventional air exhausting solenoid valve that may be frequently broken due to a repeated operation thereof in a high temperature hot water environment, so the present invention can efficiently prevent a reduction in the amount of circulated hot water or an interruption of the circulation of hot water, which may be caused by air remaining in the hot water heating tank, and can realize improved durability of the boiler by solving various problems caused by the conventional air exhausting solenoid valve.
2. Description of the Related Art
Generally, a hot water heating mat is a heating mat that is internally provided with a hot water circulation hose and is heated by hot water supplied from a small capacity boiler connected to the mat body by a connecting hose.
The hot water heating mat is advantageous in that it can solve problems experienced in a conventional electric heating mat internally provided with an electric heating wire. Here, examples of the problems experienced in the conventional electric heating mat may be harmful electromagnetic waves, a fire or an electric shock, which may be generated by the electric heating wire installed in the in mat body.
A conventional boiler used to supply hot water to the hot water heating mat typically uses an electric motor pump for circulating hot water heated by an electric heater. Due to the electric motor pump, the conventional boiler for hot water heating mats is problematic in that the electric motor pump is repeatedly operated in a high temperature hot water environment, so the pump may be easily broken and the durability of the pump is greatly reduced, and noises and vibrations generated from an electric motor of the electric motor pump during operation of the pump directly travel to the outside of the boiler, thereby causing unpleasant noise and disturbing the user or people nearby.
Another problem of the conventional boiler for hot water heating mats resides in that, when the hot water circulation hose of a hot water heating mat is folded, for example, through user carelessness, hot water may not easily flow through the hot water circulation hose resulting in overload of the electric motor pump generating a pumping force for circulating the hot water. Thus, durability of the boiler for hot water heating mats may be greatly reduced due to, for example, user carelessness.
In an effort to solve the above-mentioned problems, a convection boiler for hot water heating mats, which is configured to naturally circulate hot water in a hot water heating mat using steam pressure generated in a hot water heating tank during an operation of heating hot water, was proposed. However, this conventional convection boiler using steam pressure is problematic in that, when the hot water circulation hose of the hot water heating mat is inadvertently folded, hot water may not easily flow through the hot water circulation hose, thus excessively increasing the steam pressure to a level causing explosion of the boiler.
To solve the problems experienced in the conventional convection boiler using steam pressure, the applicant of this invention developed a boiler for hot water heating mats and filed a patent application for the boiler, and the application was granted in Korean Patent No. 10-0948908. In the boiler, a water storage tank having both a reserve water storage chamber and a hot water storage chamber therein is installed at a location above a hot water heating tank having an electric heater and is connected thereto such that, when hot water is heated by the electric heater and is discharged from the hot water heating tank to the hot water storage chamber of the water storage tank due to steam pressure formed in the hot water heating tank, the hot water can circulate in a hot water heating mat by a vacuum suction force formed in the hot water heating tank.
Described in detail, in the boiler for hot water heating mats of the present applicant, a hot water heating tank 32 is installed in a lower part inside the boiler as shown in FIG. 9, with a water level sensor 33 and an electric heater 34 installed in the tank 32. Further, a reserve water inlet port 35 is formed on a predetermined outside portion of the tank 32, and a hot water discharging port 36 and a hot water recovering port 37 having respective check valves 36a and 37a are formed on other predetermined outside portions of the tank 32. A water storage tank 38 is installed in an upper part inside the boiler. The inner space of the tank 38 is divided into a reserve water storage chamber 40 and a hot water storage chamber 50 by a partition wall 39 having an overflow opening 39a formed on the top end of the partition wall 39. In the upper wall of the reserve water storage chamber 40 of the water storage tank 38, a reserve water charging port 41 and an air exhausting port 43 are formed. Here, the reserve water charging port 41 is opened and closed by a plug 42, and the air exhausting port 43 is provided with a vaporization preventing plate 44. Further, a steam guide plate 45 extends downward from the inner surface of the upper wall of the reserve water storage chamber 40 at a location adjacent to the partition wall 39, so, when steam is discharged from the hot water storage chamber 50 via the overflow opening 39a of the partition wall 39, the steam guide plate 45 can guide the steam to a lower part inside the reserve water storage chamber 40. A reserve water outlet port 46 is formed in the lower wall of the reserve water storage chamber 40, and a water deficiency sensor 47 is installed in a lower part of the reserve water storage chamber 40. In the lower wall of the hot water storage chamber 50 of the water storage tank 38, a hot water inlet port 51 and a hot water outlet port 52 are formed. Here, the reserve water inlet port 35 of the hot water heating tank 32 is connected to the reserve water outlet port 46 of the reserve water storage chamber 40 by a reserve water supplying pipe 53 having a solenoid valve 54, and the hot water discharging port 36 of the hot water heating tank 32 is connected to the hot water inlet port 51 of the hot water storage chamber 50 by a connection pipe 49.
The above-mentioned conventional boiler for hot water heating mats is advantageous in that the water storage tank 38 having both the reserve water storage chamber 40 and the hot water storage chamber 50 is installed at the location above the hot water heating tank 32 having the electric heater 34 and is connected thereto such that, when hot water is heated by the electric heater 34 and is discharged from the hot water heating tank 32 to the hot water storage chamber 50 of the water storage tank 38 due to steam pressure formed in the hot water heating tank 32, the hot water can circulate in a hot water heating mat by the vacuum suction force formed in the hot water heating tank 32. Further, even when the hot water circulation hose of the hot water heating mat is blocked or the interior of the hot water heating tank 32 is filled with air, the solenoid valve 54 of the reserve water supplying pipe 53 connecting the hot water heating tank 32 to the reserve water storage chamber 40 of the water storage tank 38 is automatically opened. Thus, reserve water can be automatically supplied from the reserve water storage chamber 40 of the water storage tank 38 to the hot water heating tank 32, thereby preventing a reduction in the amount of circulated hot water or an interruption of the circulation of hot water, which may be caused by the blocking of the hot water circulation hose or the air remaining in the hot water heating tank.
However, the above-mentioned boiler for hot water heating mats is problematic as follows. In the boiler, the solenoid valve 54 provided to automatically supply reserve water from the reserve water storage chamber 40 of the water storage tank 38 to the hot water heating tank 32 when the hot water circulation hose of the hot water heating mat is blocked or the interior of the hot water heating tank 32 is filled with air is repeatedly operated in a high temperature hot water environment. Here, the inner diameter of a water passing orifice of the solenoid valve 54 required to be repeatedly operated in the high temperature hot water environment is excessively small, so the solenoid valve 54 may frequently malfunction due to impurities and may fail to efficiently exhaust air or to efficiently supply reserve water to the hot water heating tank, thereby greatly reducing durability of the boiler.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.